RE: Pipe and redirect STDOUT
Guys, My understanding is that there is a bug in the file extension/application to execute code, that is part of windows, that stops redirection from working if Microsoft does this "lookup" itself. Stopping it having to do this lookup, by invoking Perl.exe directly, gets around this issue. This problem has been around for as long as I can remember. Kev. -Original Message- From: Martin Leese [mailto:[EMAIL PROTECTED] Sent: 23 February 2004 05:05 pm To: [EMAIL PROTECTED] Subject: Re: Pipe and redirect STDOUT Sui Ming Louie wrote: > I have run similar batch files on NT4.0. They worked OK. At one point, I > used to think that redirection from batch files was not possible. Then I > got some insight from reading the perl2bat.bat file included with Perl. I asked the original question, so I thought I would try to summarize progress to date. First, many thanks to everyone who has responded. One poster suggested the problem might be that typing "test.pl" invoked a BAT file, and that my problem was redirection from BAT files in general. There is no "perl.bat" on my system, so this is not the problem. Also, redirection from BAT files appears to work as expected. (Also, also, there is no "perl2bat.bat" file on my system.) Another poster suggested trying "perl test.pl" and, indeed, redirection using this form of invocation works fine. This is a valid work around and, although my problem has not been solved, my problem is no longer a problem. > Martin Leese wrote: >>Hi, >> >>I know this is a really dumb question (yes, there are dumb >>questions), but I am stuck. >> >>Why can I neither pipe the output from a perl script to "more" >>nor redirect it to a file? This is under Windows NT. >> >>The following script: >> >>#! /usr/local/bin/perl >># >>use strict; >>use warnings; >>###use diagnostics; >># >>print STDOUT "Hello me"; >># >>exit(0); >> >>produces "Hello me" on the screen with the command "test.pl". >>However, the command "test.pl |more" produces a blank line, >>and the command "test.pl >test.txt" produces an empty file. >>Why? >> >>As the more intelligent amongst you will have guessed, I am >>not a Windows person. >> >>Also, while you are here, what is the difference between >>"use warnings;" and "use diagnostics;"? >> >>I am running perl, v5.8.2 built for MSWin32-x86-multi-thread, >>Binary build 808 provided by ActiveState Corp. under >>Windows NT. >> >>Many thanks for any help you can give. >> >>Regards, >>Martin Thanks again to everyone who responded, Martin ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden. TradeWeb reserves the right to monitor all e-mail communications through its networks. ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: Wierd Perl syntax ($#$dlr) explanation, please!
Dietmar, Thanks for the response. I read that in the manual but it didn't make sense to me in the way that this was being used. There is a loop and, within it, the following: next if ($#$dlr == -1); How would the awk-stuff below fit with this code above? Ta. K. Kevin Hill AVP Programmer TradeWeb Europe Ltd 99 Gresham Street London EC2V 7NG Tel: +44 (0)20 7776 3200 Fax: +44 (0)20 7776 3201 www.tradeweb.com -Original Message- From: Dietmar Maurer [mailto:[EMAIL PROTECTED] Sent: 21 November 2003 11:33 am To: Kevin Hill Subject: AW: Wierd Perl syntax ($#$dlr) explanation, please! >From perlvar: $# The output format for printed numbers. This variable is a half-hearted attempt to emulate awk's OFMT variable. There are times, however, when awk and Perl have differing notions of what counts as numeric. The initial value is ``%.ng'', where n is the value of the macro DBL_DIG from your system's float.h. This is different from awk's default OFMT setting of ``%.6g'', so you need to set $# explicitly to get awk's value. (Mnemonic: # is the number sign.) Use of $# is deprecated. So $#$dlr is $# followed by $dlr. Dietmar > -Ursprüngliche Nachricht- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Auftrag von > Kevin Hill > Gesendet: Freitag, 21. November 2003 12:12 > An: Active Perl Mailgroup (E-mail); Perl Win32 Users (E-mail) > Betreff: Wierd Perl syntax ($#$dlr) explanation, please! > > > > Guys, > > Just found this in some of our legacy Perl code - any idea what > it does? $dlr is a scalar, containing the name of a dealer. > > $#$dlr > > Thanks for any help that can be given. > > Kev. > > Kevin Hill > AVP Programmer > > TradeWeb Europe Ltd > 99 Gresham Street > London EC2V 7NG > Tel: +44 (0)20 7776 3200 > Fax: +44 (0)20 7776 3201 > www.tradeweb.com > > > > > > This e-mail may contain confidential and/or privileged > information. If you are not the intended recipient (or have > received this e-mail in error) please notify the sender > immediately and destroy this e-mail. Any unauthorized copying, > disclosure or distribution of the material in this e-mail is > strictly forbidden. TradeWeb reserves the right to monitor all > e-mail communications through its networks. > > > ___ > Perl-Win32-Users mailing list > [EMAIL PROTECTED] > To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
Fork/wait generating GPF at 0x0000000c in Perl.exe
Guys,
I am running ActiveState Perl v5.8.0 straight out of the box, with the following test
piece of code for forking and waiting for child processes. Perl.exe generates a GPF at
0x000c as the child is quitting. Anyone have any ideas what might be going wrong?
I based the code on the code extract within the fork documentation in the Camel book.
The output up until just before the GPF is as follows:
Parent. Child is -108
Child: started: -108
Parent waiting for kiddies...
Child: -108 about to exit.
Sorry if this topic has already been done to death, but I had a search and couldn't
find anything that appeared relevant.
Ta.
Kev.
sub InvokeCmdAsAsyncProcess
{
my( $exec_line, $dummy ) = @_;
my $pid;
FORK:
{
if( $pid = fork ) {
# Parent process here.
# Child pid in $pid.
print "Parent. Child is $pid\n";
}
elsif( defined( $pid ) ) {
# Child process here.
# parent process pid is available with getppid
print "Child: started: $$\n";
sleep 10;
#system (1, "$exec_line");
print "Child: $$ about to exit.\n";
exit 0;
}
elsif( $! =~ /No more process/ ) {
# EAGAIN, supposedly recoverable fork error
print "Forking having problems. Retrying\n";
sleep 2;
redo FORK;
}
else
{
# Wierd fork error.
die "Can't fork: $!\n";
}
}
return $pid;
} # end of InvokeCmdAsAsyncProcess
my %pids;
my $pid;# pid of most recent child process.
foreach $filename (@files)
{
my $exec_line = "$filename > $filename.log";
print "Executing $exec_line\n";
$pid = InvokeCmdAsAsyncProcess( $exec_line );
if( defined( $pid ) ) {
$pids{$pid} = $pid;
}
}
print "Parent waiting for kiddies...\n";
while( ($pid = wait()) != -1 ) {
print "Parent: Child $pid exitted with status: $?\n";
}
print "Parent after wait.\n";
Kevin Hill
AVP Programmer
TradeWeb Europe Ltd
99 Gresham Street
London EC2V 7NG
Tel: +44 (0)20 7776 3200
Fax: +44 (0)20 7776 3201
www.tradeweb.com
This e-mail may contain confidential and/or privileged information. If you are not the
intended recipient (or have received this e-mail in error) please notify the sender
immediately and destroy this e-mail. Any unauthorized copying, disclosure or
distribution of the material in this e-mail is strictly forbidden. TradeWeb reserves
the right to monitor all e-mail communications through its networks.
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